I. Field of the Invention
The present invention relates generally to tool sharpening fixtures and, more particularly, to such a fixture particularly adapted for sharpening rotary cutting tools.
II. Description of the Prior Art
There are a number of special rotary cutting tools which are used in machining operations and which are specially constructed for a particular operation. Such cutting tools typically comprise two or more cutting edges having a predetermined radial and/or axial relief and with a flute extending between adjacent cutting edges.
After the use of the cutting tool in machining operations, the cutting tools become dull and require either sharpening or replacement. Most machine shops which utilize such special cutting tools, however, do not have the proper equipment to sharpen these cutting tools when they become dull since it is necessary to sharpen these tools so that the cutting edges have the proper radial and axial relief for their proper cutting action. Consequently, when these cutting tools become dull it has been the previous practice to either discard the cutting tool or to send the cutting tool to a special shop having the equipment necessary to regrind or sharpen the cutting tools and still retain the proper axial and radial relief on the cutting edges.
The previous practice of discarding the dull cutting tool and replacing it with a new one is unduly expensive. Sending the dull cutting tool to a shop having the equipment necessary to resharpen the cutting tool with the proper radial and axial relief is less expensive than the total replacement of the cutting tool but often times requires a prolonged period of time before the sharpened cutting tool is returned to the user. When a particular cutting tool is required to finish a particular job, the time required to have a dull cutting tool sharpened oftentimes results in unsatisfactory delays in completing the job.
There have, of course, been a number of previously known tool sharpening fixtures which are designed to hold and rotate a cutting tool to sharpen the cutting edges, typically by grinding the outer periphery of the cutting edges. Some of these previously known sharpening fixtures have also included means for varying the axial and/or radial relief on the cutting edges of the tool.
These previously known tool sharpening fixtures, however, are unduly complex and expensive in construction. For many machine shops or the like which require only occasional resharpening of their special cutting tools, these previously known fixtures are economically infeasible. For this reason, many machine shops still either discard their dull cutting tools or send their dull tools to machine shops with special equipment for resharpening these tools.